The field of the present invention is catalytic converters and their construction.
Catalytic converters for use in vehicles, and more recently motorcycles in particular, have been developed which employ two catalytic elements through which exhaust gases are passed. The catalytic elements are generally formed of a porous or honeycomb structure. Such structures are generally quite fragile and subject to cracking, chipping and the like. In the rough vibrational environment of a motor vehicle, careful placement of such catalytic elements becomes necessary.
Catalytic converters employing multiple catalytic elements have been known and have included the location of the catalytic elements in series within a cylindrical housing. The catalytic elements are contained within cushion members comprising annular rings fitted around the catalytic elements and cushion rings abutting against the ends of the elements. The cushioned elements must then be retained more rigidly within the casing. Set plates are incorporated into the assembly at each end of the catalytic elements such that the cushioned catalytic elements including the cushion rings are held rigidly from moving along a coaxial centerline from the desired location.
Because of the fragile nature of the catalytic elements, it has been found necessary to insure that each of the set plates is properly positioned in an orientation truly perpendicular to the coaxial centerline of the cylindrical casing. Consequently, the set plate in the middle has been carefully positioned centrally within the cylindrical case and spot welded in place. Substantial effort and cost is required to properly locate and weld the set plate in position. The catalytic elements with their cushioning elements are inserted from either end of the casing into abuttment against the middle set plate. End set plates are then positioned outwardly of the catalytic elements in the cylindrical case.
If the set plates are not properly oriented in a perpendicular position relative to the cylindrical casing, and if those set plates are locked in place, unbalanced stresses on the catalytic element can result. Because of the fragile nature of such elements, damage to the elements can occur under such circumstances. Such damage might occur during the initial assembly when compression is applied to the assembly. Alternately, vibrational loading under such conditions may result in damage.